Outside of very small applications, Nikola Tesla’s ideas about transmitting serious energy without them were not very real. Of course, we can draw microwatts from radio signals in the air and if you want to bring your phone inside Just You can charge it in the right place. But sending power to your laptop anywhere in your home is still a pipe dream. Sending electricity from a generating station to a dozen homes without it is even more fantastic. Or is it? [Paul Jaffe] The Naval Research Laboratory thinks this is not fantastic at all and explains why in a post on IEEE Spectrum.
Historically, there have been attempts to move a lot of energy around wirelessly. In 1975, researchers transmitted energy across a lab using microwaves at 50% efficiency. They were actually making a case for reducing energy from solar power satellites. According to [Jaffe] The secrets are even beyond the microwave. A Navy 2019 display has reached 400 watts over 300 meters using a laser. The use of a tightly limited beam over a single consistent wavelength allows for highly efficient photovoltaic cells that may exceed the type of solar light we are accustomed to receiving.
Wait. Navy. High power laser beam. Oh, right? According to [Jaffe], It is a factor of how much energy is in the beam with the actual wavelength involved. The 400-watt ray, for example, was in a virtual enclosure that could sense any object near the original ray and dissipate energy.
Remember, 400 watts is not enough to get a hair dryer. Also, a point-to-point transmission with a laser is good for sending power to remote communities, but not great for keeping your laptop charged wherever you go.
Still, it sounds like exciting work, and although it may not be Tesla’s perfect vision, it seems that laser transmission may be closer than it seemed a few years ago. We’ve seen similar systems that employ security sensors, but they’re all relatively low power. Although we still want to know what’s going on in Milford, Texas.